Ok i will be the Solo guy here
Generation X was better period.
As far as New Mutants go the only person i ever cared for was cannonball (now he is in my top 5 or so x men ever but still) And i seem to like him better outside the group dynamic, i would love to see him shine as leader of anew team who didnt see him as "the hill billy sam who just cant get it done) which seems to be what they thought of him thus why Dani was always leader or atleast co leader
Generation X i think was killed due to writers after that, the powers imo were more gritty and interesting. they showed the downfall of mutant powers (similar to how Morrison did) only they seemed to make them more combat ready and intersting then morrisons run imo. Even skin whose power was disgusting and would suck ass learned to use it in combat, and imo was a cool character. Chamber whose entire chest got blow off, man that sucks right? Then people like penanace you never really got to understand. New mutants lasted longer and have more affect on today's X men simply because they were written by Chris Claremont and when he left them he used his other characters (such as cannonball) and mentioned his stuff in other main X men titles (he also wrote both new mutants and x men at once)
while Lobdell and whoever took over the book after him, didn't have claremonts swag in the X verse (and i think lobdell was gone by the time teh series was over) and the writers who came after just didn't care about those characters when they could write Cyclops, Wolverines ect.
Also keep in Mind imo the Best Emma Frost ever, was the Gen X emma.
Generation X is alot like what i am afraid will happpen to the new X men and lights of alot more recent history. THey were a nice story that was told and had some good characters, but once the original writer was gone the ones after wanted to do thier own thing, and that doesnt include underdeveloped characters, they want stars.
So yea My 3 cents
GO GEN X!